Various bimetallic salts and derivatives thereof have been employed in the preparation of scavengers or complexing agents for various liquids such as olefins, aromatics, carbon monoxide and the like as disclosed in U.S. Pat. Nos. 3,592,865; 3,647,843; 3,651,159; 3,754,047 and 3,755,487. One of the more popular bimetallic salts is cuprous aluminum tetrahalide (CuAlX.sub.4) generally prepared by reacting a cuprous halide with an aluminum trihalide in a suitable solvent.
During prolonged use of these complexing agents, particularly when the feed streams contain olefins and the solvent is an aromatic solvent such as toluene, these agents become contaminated with alkylated aromatics i.e. the aromatic solvent is alkylated by reaction with the olefins which changes the boiling point thereby lowering the efficiency of the recovery process. Disposal of the spent complexing solutions become a problem because they also contain cuprous halides, mostly in the form of CuAlX.sub.4, and the copper ions are not acceptable in waste treatment bio ponds. Therefore there has not been discovered a method for removing the copper from such spent or used complexing solutions.